Scale



` Oct. 13, 1931.

w. F. sTlMsoN ET A1. 1,827,048

SCALE 4 SheetSwSheet 3 Filed Dec. l2, 1927 CCL 13, 1931* w. F` STIMPSON ET AL. 1,827,048

SCALE Filed Dec. 12, 19.27

4 Sheets-Sheet 4 Wfl amaranto/w Patented Oct. 13, 1931 UNITED STATES PATENT OFFICE WALTER F. STIMPSON AND WILLISKE. FINCH, OF LOUISVILLE, KENTUCKY; SLIDFINGH y ASSIGNOR TO'SAID'STIMPBON SCALE Application led December 12, 19537.k Serial lNo. 239,588.

The invention relates to spring balance scales and has more particular reference to the type of construction provided with opposed springs for automatic temperature compensation. In the present state of the art various attempts have been made to effect automatic temperature compensation by the use of opposed springs. It has been found, however, that while such Constructions compensate to a considerable degree, they do not effect complete compensation, so that the operation of the scale under different temperatures is not quite accurate.

It is the object of the present invention to obtain a construction in which there is accurate compensation for all variations in temperature and further to obtain certain other advantages as hereinafter set forth.

In the drawings; Figure l is a vertical section through the pedestal of the scale showing the weighing mechanism and indicator in elevation.

Figure 2 is a horizontal section taken sub stantially on line 2 2 of Figure 1.

Figure 3 is a plan View of the thermostatic adjustment means.

Figure 4 is a front elevationl thereof.

Figure 5 is a section showing the means for adjusting spring tension.

Figure 6 is a plan view thereof.

Figure 7 is a cross section throughv the thermostat.

Figure 8 is a cross section on line 8--8 of Figure 1.

Figure 9 is at diagrammatic plan view of the platform levers.

Figure l0 is a pers ective 'view of a portion of the frame an main platform lever showing the manner of fulcrumin the latter.

Figure 11 is a similar view s owing the4 companion lever and the manner in which it is fulcrumed. A

Our improvements are applicable to'yvarious types of scales such as counter and portable platform scales, etc. As shown in Figure l A is the scale base containing the platform levers and B is thev pedestal or frame rising from one end of said base and carry? ing the weighing mechanism. This pedestal B is provided at its upper end with a laterk'thereto b connecte ying the nose of the member P.-

ally enlarged portion C for receivinr the weighing levers and cut away front an rear to expose these levers to view. Arranged centrally within the portion C are the vertically extending bracket members D and D which form fulerum bearings for the lever E. This lever has the central'fulcrum pivot F and approximately equally spaced upon opposite sides thereof ithe knife edged pivf ots G, G for attachment of the weighing springs H, H. The latter extend downward within the hollow pedestal and are anchored at their lower ends to bearings I, I. Mounted on top of the portion C is the indicator J which is operated by a pinion K and rack L. Instead, however, of connecting the rack bar L directly to the lever E it is actuated through the medium of a second lever M arranged below the lever E and connected the link N. The lever E is also to the platform leversthrough a steelyard yrod O. Y

As the springs H and H are of approxi'- mately eal tension and are connected to the lever 4 at points approximatel equall spaced on opposite sides of the fu crum 152i it is obvious that the reaction of said springs on the lever tends to hold the same in horizontal or one-half capacity position. To normally hold the lever and indicator mechanism in zero position and to offset the weight of platform and levers, it is necessary to introduce a gravity load. This, as shown, comprises a weight E on the lever E to the right offthe fulerum F and the weight M on the lever N to the left of its fulerum pivot M".v The arrangement is such that any tilting of the scale from the level will not affect gravity loading las the sum of the reactions of the two weights E and M will remainI constant `in each position.

To facilitate adjustment for sealing the fulerum for the lever M which is a lever of the third class, is adjustably mounted on a bracket P secured to one side of the frame C. The fulerum member P is of angular form with the angle thereof pivotallr engagertically and horizontallyadjusting screws P2, Pa secure the member P/ to the member P and pivots G, G.

permit of rocking the same to different positions of adjustment. This will displace the lever M longitudinally with respect to the lever E which permits of arranging the lilik N connecting these levers in approximately vertical position at one half capacity posi-A ature changes to a considerable extent willv not entirely do so. Vile have. therefore, introduced a further compenmtingfeature which is arranged between the lever M and its connection to the rack -bar L. As shown in Figures 3 and 4 the rack L is connected by a rod L and a lateral extension L2 there- ,of to the V-shaped bearing Q Vfor engaging the knit-'e edged pivotQ. The latter is mounted on the roller carriage R'which en-` gages a channel extension R of the lever M. S is a` lug depending from the carri age R and passing through aV slot in the channel member R. S is a horizontally extending pin secured to the lug S, and T and T are spirally coiled thermostatic bars attached at their inner ends to the pin S and at their outer ends anchored by rods U to the lever M. The arrangement is such that temperature changes by contracting or expanding the thermostatic spiral bars T, T Will cause the carriage R'to move outwardly or inwardly in the channel R thereby increasing or shortening the effective length of the lever M operating upon the rack Vbar L. The 'amount of adjustment required is very slightas it is only necessary to supplementand .compensate the action of the opposed springs H and H. The rack bar L is partially counter-balanced by the outwardly and down-A wardly extending arm L3 and weight L4 to reduce the lateral thrust ot said rack bar against the pinion K.

For adjusting the tension of the springs H they are attached to the bearings engaging the pivots G, G by the followingconstruction;

V are the loop bearings for engaging the V is a threaded rod depending from the loop bearing V andswivelled therein. V2 is a pronged member threadedly engaging the rod V and havingthe prongs thereof inserted between convolutions of the Ithe disk. The arrangement is such' that by turning the disk, the member V2 will be adjusted so as to either lengthen or shorten the free portion of the spring H. The total amount of adjusting is only one convolution of the spring and the amount of angular adj ustment indicated on the disk by numerals or other characters placed thereon, the chief object being to prevent the excessive adjustment of one spring without similar adjustmontrof thecother. Also, it'necessary, the

vendport-.ion H?. of the spring can be sprung outward and placed on the other side of the finger VG permitting of another revolution of adjustment.

lVhere 'the scale frame is out ol level the divided weights respectively on the levers E and M will compensate as has been previously described. It, however. the platform levers were free to oscillate laterally, this would swingthe steelyard rod in relation to the lever E and wouldthus introduce another inaccuracy. lVe have guarded 'against this difficulty by so mounting the platform lever directly attached to the steelyard rod .as to hold it from lateral swinging.V movement. Thus as shown this lever YV has its fulcrum pivots lV engaging fixed bearings on the lugs lV? projecting inward from the stationary frame A. The forwardly projecting arm i ot this lever is attached to the steelyard O. 9

Thus where the scale trame is. tilted out of level neither the lever \V nor the steelyard is capable of swinging, to alter the relation of said steelyard to the lever E: The weighing platformis, however.' supported on oscillatory looped hearings X and the companion platform lever XV* is ulcrumed upon swinging looped bearings X. This will permit perfect freedom of. movement of the platform whether the scale is in or out of level but, as before stated7 without permitting any lateral displacement of the steelyard O.

lVhat we claim as our invention is l. In a scale, the combination With a lever of opposed weighing springs connected to said lever forvpartially compensating t'or temperature changes and thermostatically operated meansiior supplementing the compensation.

2.Ina scale.; the combination with a lever of opposed weighing .springsA connected to said lever forfpartially compensating for temperature changes7 gravity loading means for oneofsaid springs arranged to compensate for changes in level and thermostatically operated means 'for supplementing the temperature compensation.

3. In a scale the combination with a wei ghingplatformand indicator and intermediate mechanism including a lever, of opposed weighingsprings, reacting upon said lever and partially-eompensating or temperature changes-'gravity loading means for one of said` springs arranged to be unaffected by changes in level and thermostatically operated means for supplementing the temperature compensation of said opposed springs.'

1i. In a scale the combination of a pair of parallelly and vertically arranged springs, oi' a lever to which said springs are attached at points approximately equally spaced on opposite sides of the fulcrum thereof, a second lever operatively arranged below the first mentioned lever, weights on said levers acting in unison to load one of said springs and reacting equally thereupon, said weights bein@r arranged respectively on opposite sides of their fulcrums, a steelyard rod connected to said first mentioned lever, an indicator and a connection between said second mentioned and said indicator.

5. In a scale, the combination with a pair of parallelly and vertically arranged springs, of a lever to which said springs are attached at points approximately equally spaced on opposite sides oiI the fnlcrum thereof, a lever arranged below and parallel to said first mentioned lever, weights on said levers acting in unison to load one or" said springs and reacting equally thereupon, said weights being arrange-d respectively on opposite sides of their fulcrums, a steelyard rod connecting said first mentioned lever, an indicator, a connection between said indicator and said second mentioned lever adjustable on the latter tov. :d and from its tulcrum and a thermostat operating to adjust said connection and supplementing the temperature compensation of said opposed springs.

(l. In a scale, the combination with a pair ot parallelly and vertically arranged springs, of a lever to which said springs are attached at points approximately equally spaced on opposite sides oi the fulcrum thereof, a lever arranged' operatively below said first mentioned lever, weights on said levers acting in unison to load one of said springs and reacting equally thereupon, said weights being arranged respectively on opposite sides of their tulcrums, a steelyard rod connecting said first mentioned lever, an indicator, a roller carriage on said second mentioned lever movable toward and from the fulcrum thereof, a. connection between said carriage and said indicator and a thermostat for adjusting said carriage on said lever supplementing the temperature compensation of said opposed springs.

7 In a scale the combination with a base, platform levers therein, a hollow pedestal rising from one end of said base, a lateral enlargement at the upper end of said pedestal, a lever centrally fulcrumed and extending oppositely into said lateral enlargement, springs attached to said lever at points approximately equally spaced on opposite sides of the fulcrum thereof and extending downward through said hollow pedestal, an anchorage for the lower end of each spring, a lever arranged below said v lirst mentioned on said levers actingin unison to load one of sald springs and reacting equall'7 thereupon,

said weights being arranged respectively on opposite sides of theirfulcrums, a steelyard rod connecting said irst mentioned lever with the platform levers in the base, an indicator mounted on said pedestal and a connection between said indicator and said second mentoned lever.

A 8. In a `scale a thermostatic adjustment comprising a lever, a channel extension thereof, a rollery carriage in said channel extension, a lugy depending from said roller carriage passing through a slot in said channel, a spiral thermostat having one end connected to said channel and the opposite end to said lug, a knife-edged'fpivot `mounted on said carriage and a cooperating bearing for said knifeedged pivot, f

9. In a scale, the combination of a pair ory parallelly and vertically arranged springs, a lever to which said springs are attached at points approximately equally spaced on opposite sides of the fulcrum thereof, a lever arranged operatively below said iirst mentioned lever and connected thereto, weights on said levers acting in unison to load one of said springs and reacting equally thereupon,

said weights being arranged respectively on opposite sides of their fulcrums, an indicator, a connection between said second mentioned lever and said indicator, a steelyard rod, connected to said lirst mentioned lever, a platform lever to which said steelyard rod is connected, a fulcrum bearing for said platform lever holding the same against lateral movement, a cooperating platform lever, a platform supported thereon and bearings for said platform and for said second platform lever permitting lateral movement thereof.

10. In a spring scale, adjustment means for spring tension comprising a threaded shank, a pronged member engaging the convolutions of said spring and threaded to engage said shank, a disk sleeved on said shank adjacent to said pronged member and rotatably coupled therewith, a linger projecting from said disk, a projection from the end convolution of said spring bent to engage said linger, and a lock nut on said shank for holding said disk and pronged member from movement.

1l. In a scale, the combination with a lever, of weighing springs connected to said lever for partially compensating for temperature changes, a second lever operatively arranged below and connected to the lirst mentioned lever, an indicator and a connection between said second lever and said indicator including auxiliary compensating means.

12. In a scale, the combination with a lever, of weighing springs connected to said lever for partially compensating for temperature changes, a second lever operatively arranged below and connected tothe first mentioned lever, an indicator, a connection between said second lever and said indicator including auxiliary compensating means, and gravity "l loading means tor said first mentioned-lever to bring the indicator to the zero point.

13. In a scale, the combination of a pair of parallelly and vertically arranged springs,

l f of a lever to which said springs areattaclied at points approximately equally'spaced on opposite sides of the fulcrum thereof for pai'- tiallj; compensating for temperature changes, a second lever operatively arranged below 15 and connected to the irst mentioned lever,

L l a steelyard rod connected to said first mentioned lever. an indicator and a connection between said second lever and said indicator including auxiliary compensating means.

14. In a scale, the combination of a pair of parallelly and vertically7 arranged springs, of a lever to `which saidsprings are attached at points approximately equally spaced on opposite sides of the fulcrum thereof for par- 2@ tially compensating for temperature changes, a second lever operatively arranged below and connected to the first mentioned lever, a steelyard rod connected to said first mentioned lever, an indicator, a connection betiveen said second lever and said indicator including auxiliary compensating means and a gravity loading means for said rst mentioned lever to normally hold the lever and indicator mechanism in zero position.

35i In testimony whereof We aix our signa.-

tures.

IN ALTER F. STIMPSON. WILLIS E. FINCH. 

